Schizachyrium plant named ‘MinnblueA’

ABSTRACT

A new cultivar of  Schizachyrium scoparium , ‘MinnblueA’, that is characterized by its tall, narrow, upright form that does not lodge and its unique foliage color that is blue with highlights of burgundy in summer changing to a bright mixture of colors in fall including tones of purple, blue, red, pink, burgundy, and orange. ‘MinnblueA’ is further characterized by its ability to grow in a wide range of soil types including heavy clay, dry, and alkaline soils.

Botanical classification: Schizachyrium scoparium.

Varietal denomination: ‘MinnblueA’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofSchizachyrium scoparium and will be referred to hereafter by itscultivar name, ‘MinnblueA’. ‘MinnblueA’ represents a new cultivar oflittle bluestem, an ornamental grass grown for landscape use.

The inventor discovered and selected the new cultivar, ‘MinnblueA’, in acultivated field in St. Paul, Minn., in the summer of 1996. ‘MinnblueA’was discovered as a naturally occurring variant seedling in a cultivatedfield sown for field evaluations of little bluestem. The field fromwhich ‘MinnblueA’ was selected was sown with seed collected in the fallof 1995 from a field of open pollinated, unnamed plants of Schizachyriumscoparium grown for seed production in Benton County, near Princeton,Minn. The seed collected from the unnamed plants of Schizachyriumscoparium was bulked from several individuals, grown in the greenhouseand then plants were transplanted into the cultivated field in St. Paul.It is not possible to identify the parents for ‘MinnblueA’.

The new cultivar ‘MinnblueA’ is unique in several characteristics, whichmakes this new invention unlike any other known cultivars or varietiesof Schizachyrium scoparium known to the inventor. ‘MinnblueA’ has ataller, more upright form than is typical of little bluestem.‘MinnblueA’ has dark blue to burgundy foliage during the summer, turningred to purple and violet in the fall. The summer and fall color isunique on a plant that has a tall columnar stature.

Asexual reproduction of the new cultivar was first accomplished by rootdivision in St. Paul, Minn. in 1999 by the inventor. The vegetativepropagules of this cultivar have been determined to be stable and arereproduced true to type in successive generations.

SUMMARY OF THE INVENTION

The following traits have been repeatedly observed and represent thecharacteristics of the new cultivar. ‘MinnblueA’ has not been observedunder all possible environmental conditions. The phenotype may varysomewhat with variations in temperature, day length, light intensity,soil types and water and fertility levels, without, however, anyvariance in the genotype. The measurements, observations anddescriptions that follow describe plants grown outdoors and observed forsix years in St. Paul, Chaska, Morris, Crookston and Plymouth, Minn.These attributes in combination distinguish ‘MinnblueA’ from any knownselections of Schizachyrium scoparium known to the inventor.

-   -   1. The plant growth habit of ‘MinnblueA’ is upright and narrow        to upright open. The habit of the species is much looser and        open, with arching and lodging typical.    -   2. The height of ‘MinnblueA’ is 120-140 cm, which is taller than        most little bluestem, especially little bluestem in the upper        Midwest. The species is typically 20-100 cm, although in        southern US, plants can be taller, to 150 cm.    -   3. Summer color of ‘MinnblueA’ foliage is medium to light blue,        with highlights of dark red and purple. The flowering culms are        dark burgundy red. The species color is much more variable from        green, to blue green and olive green with similar flowering culm        color.    -   4. Fall color of ‘MinnblueA’ foliage is much brighter than the        species, with light purple, red and pink colors including light        blue, burgundy and orange. The fall foliage is often a rainbow        of colors. The species tends to be more uniform in color with        fewer colors represented.    -   5. ‘MinnblueA’ is tolerant of a wide variety of soils and has        been grown on heavy clay soils as well as dry sites, which is        typical of little bluestem. ‘MinnblueA’ is tolerant of high pH        or alkaline soils and drought once established.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying photographs were taken in Chaska and Plymouth, Minn.and illustrate the characteristics of the new cultivar ‘MinnblueA’.

The photograph in FIG. 1 depicts the plant habit and foliage colorationof ‘MinnblueA’ as observed in November.

The photograph in FIG. 2 depicts four plants of ‘MinnblueA’ grownside-by side and illustrates the foliage color in September and theconsistency of characteristics of ‘MinnblueA’.

The colors in the photographs are as close as possible with thephotographic and printing technology utilized. The color values cited inthe detailed botanical description accurately describe the colors of thenew little bluestem.

DETAILED BOTANICAL DESCRIPTION

The following is a detailed description of the new cultivar as grown infive outdoor field settings for six years from a single plant from thecultivated field in St. Paul, Minn. The color names and numbers refer tothe 1995 Royal Horticultural Society's Colour Chart, London, England;except for general color terms of ordinary dictionary significance areused.

-   Botanical classification: ‘MinnblueA’ is a cultivar of Schizachyrium    scoparium.-   Common name: ‘MinnblueA’ little bluestem.-   Parentage: ‘MinnblueA’ is a naturally occurring variant seedling    grown from seed collected from open pollinated parents that were    growing in a field of unnamed plants of Schizachyrium scoparium.-   General description:    -   -   Blooming period.—September and October, with seed forming in            October.        -   Plant habit.—Herbaceous perennial grass, upright and narrow,            thick fine textured foliage, long-lived.        -   Height and width or spread.—100-138 cm height in bloom,            60-85 cm in width. Moderate vigor.        -   Hardiness zone.—USDA Zones 3-9.        -   Culture.—Grows well in full sun, in most soils. Tolerant of            drought and alkaline soils.        -   Diseases and pests.—Schizachyrium scoparium is relatively            free of disease. No susceptibility of resistance to disease            or pests has been observed for ‘MinnblueA’.        -   Root description.—Fibrous, wiry, light brown numerous roots,            30-90 cm in length, up to 1 cm in diameter, plants are deep            rooted.-   Growth and propagation:    -   -   Propagation.—Root division, probably basal stem cuttings and            tissue culture.        -   Growth.—Plants develop into a one-gallon container plant in            10-12 weeks when grown in a greenhouse with ambient lighting            and an average temperature of 68 degrees F.-   Culm (stem) description:    -   -   General.—Cylindrical, solid, thin but strong, erect, upper            half freely branching, sheaths often grayish villous.        -   Culm color.—Red-purple 59A; to violet 85A; to violet blue            92A and 92B.        -   Culm size.—2-4 mm in diameter, averaging 140 cm in height            from the base to the tip of the flower panicle.        -   Stem surface.—Glabrous.        -   Internode length.—16 to 19 cm at the base, decreasing to            15-13 mid-culm, reduced to 6-9 cm near the summit.-   Foliage description:    -   -   Leaf shape.—Linear, sparsely pilose at their junction, flat.        -   Leaf division.—Simple, margins entire.        -   Leaf base.—Sheathed to base of the culm.        -   Leaf venation.—Parallel, foliage color can vary from top to            bottom.        -   Leaf width.—3-6 mm wide, average of 4 mm.        -   Leaf length.—Basal leaves 53-60 cm, mid-culm foliage            30-40 cm. near the apex of the culm 10-20 cm.        -   Leaves per culm.—Typically 4-7.        -   Leaf surface.—Glabrous.        -   Leaf collar type.—Continuous.        -   Leaf arrangement.—Alternate, 2 ranked.        -   Leaf auricle.—Not present.        -   Leaf persistance.—Foliage dries but persistent through            winter.        -   Leaf attachment.—Sheathed.        -   Ligule.—1 mm in width, membranous.        -   Leaf color (upper and lower surface).—Summer: blue-green            122C and 122D to greyed green 189 B and 189C with tips of            greyed purple, 187 A and 187B. Fall: greyed colors of orange            171 A and 171B; to red 180A, 182A and 182B; to purple 184B,            184C, 185C and 186C.-   Flower description: Flowers are as typical of Schizachyrium    scoparium, with multiple, typically 3-5, racemes present per    flowering culm. Racemes are 10-15 cm in length and red-purple 59A;    to violet 85A; to violet blue 92A and 92B in color. Spikelets are    sparse along racemes and arranged in pairs at each node of an    articulate rachis, one sessile and perfect, the other pedicellate    and either staminate, neuter, or reduced to a pedicle. Spikelets    appressed to the rachis, the sessile spikelet falling attached to a    pedicle and a section of the rachis. Sessile spikelet 6-8 mm long,    fertile, 8-15 mm awned, the pediceled spikelet reduced but usually    present, short awned. Glumes of the sessile spikelet large and firm.    Lemmas of the sterile and fertile florets thin and membranous.    Rachis and pedicels of the sterile spikelet often villous, sometimes    conspicuously so. Peduncle is an average of 1.5 mm in diameter,    ranges from 0 to 8 cm in length and color is red-purple 59A; to    violet 85A; to violet blue 92A and 92B. Reproductive organs are very    small, fleeting or scarce in presence and therefore difficult to    describe. The lastingness of the inflorescence is about two weeks.-   Caryopsis: Lemma and palea adhering to the caryopsis, actual    caryopsis very small and fine, less than 1 mm.

1. A new and distinct cultivar of Schizachyrium plant named ‘MinnblueA’as herein illustrated and described.